Apparatus for installation in aircraft for receiving fuel and other liquids in flight and control means therefor



April 14, 1953' R. F. WORLIDGE 2,534,926 APPARATUS FOR INSTALLATION mAIRCRAFT FOR RECEIVING FUEL AND OTHER LIQUIDS IN FLIGHT AND CONTROLMEANS THEREFOR Filed Jan. 1'7, 1950 15 Sheets-Sheet l April 14, 1953 R.F. WORLIDGE 2,634,926

APPARATUS FOR INSTALLATION IN AIRCRAFT FOR RECEIVING FUEL AND OTHERLIQUIDS IN FLIGHT AND CONTROL MEANS THEREFOR Filed Jan. 17, 1950 15Sheets-Sheet 2 lnven75r Aria/we) Apnl- 14, 1953 R. F. WORLIDGE 2,634,925

APPARATUS FOR INSTALLATION IN AIRCRAFT FOR RECEIVING FUEL AND OTHERLIQUIDS IN FLIGHT AND CONTROL MEANS THEREFOR Filed Jan. 17, 1950 15Sheets-Sheet s hive/7 75,-

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R. F. APPARATUS FOR INSTALLATION IN AIRCRAFT FOR RECEIVING FUEL ANDOTHER LIQUIDS IN FLIGHT AND CONTROL MEANS THEREFOR l5 Sheets-Sheet 4April 14, 1953 7 Filed Jan. 17, 1950 FIG. 3

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APPARATUS FOR INSTALLATION IN AIRCRAFT FOR RECEIVING FUEL AND OTHERLIQUIDS IN FLIGHT AND CONTROL MEANS THEREFOR Filed Jan. 17, 1950 15Sheets-Sheet 5 P" 1953 R. F. WORLIDGE APPARATUS FOR INSTALLATIGN INAIRCRAFT FOR RECEIVING FUEL AND OTHER LIQUIDS IN FLIGHT AND CONTROLMEANS THEREFOR Filed Jan. 17, 1950 15 Sheets-Sheet 6 Qmi //7 van 7%-April 14, 1953 R. F. WORLIDGE 2,634,925

APPARATUS FOR INSTALLATION IN AIRCRAFT FOR RECEIVING FUEL AND OTHERLIQUIDS IN FLIGHT AND CONTROL MEANS THEREFOR Filed Jan. 17, 1950 15Sheet s-Sheet 7 MVP/173 Ir. 6. LU

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APPARATUS FOR INSTALLATION IN AIRCRAFT FOR RECEIVING FUEL AND OTHERLIQUIDS IN FLIGHT AND CONTROL MEANS THEREFOR Filed Jan. 17, 1950 15Sheets-Sheet 9 m M M Fm,

April 14, 1953 liF. WORLIDGE 2,634,926

APPARATUS FOR INSTALLATION IN AIRCRAFT FOR RECEIVING FUEL AND OTHERLIQUIDS IN FLIGHT AND CONTROL MEANS THEREFOR Filed Jan. 17, 1950 15Sheets-Sheet 1O Apnl 14, 1953 R. F. WORLIDGE 2,634,926

APPARATUS FoR INSTALLATION IN AIRCRAFT FOR RECEIVING FUEL AND OTHERLIQUIDS IN FLIGHT AND coNTRoL MEANS THEREFOR Filed Jan. 17, 1950 15SheetsSheet ll /n ve075r R. F. WORLIDGE 2,634,926 APPARATUS FORINSTALLATION IN AIRCRAFT FOR RECEIVING FUEL AND OTHER LIQUIDS IN FLIGHTAND CONTROL MEANS THEREFOR l5 Sheets-Sheet 12 April 14, 1953 Filed Jan.17, 1950 In yen/5r Apnl 14, 1953 R. F. WORLIDGE 2,634,926

APPARATUS FOR INSTALLATION IN AIRCRAFT FOR RECEIVING FUEL AND OTHERLIQUIDS IN FLIGHT AND CONTROL MEANS THEREFOR Filed Jan. 17, 1950 15Sheets-Sheet 1s Apnl 14, 1953 R. F. WORLIDGE 2,634,926

APPARATUS FOR INSTALLATION IN AIRCRAFT FOR RECEIVING FUEL AND OTHERLIQUIDS IN FLIGHT AND CONTROL MEANS THEREFOR Filed Jan. 17, 1950 15Sheets-Sheet l4 Apnl 14, 1953 R. F. WORLID GE 2,634,926

APPARATUS FOR INSTALLATION IN AIRCRAFT FOR RECEIVING FUEL AND OTHERLIQUIDS IN FLIGHT AND CONTROL MEANS THEREFOR Filed Jan. 1'7, 1950 15Sheets-Sheet 15 FIG. /8.

//1 ran 75/ Patented Apr. 14, 1953 APPARATUS FOR INSTALLATION IN AIR-CRAFT FOR RECEIVING FUEL AND OTHER LIQUIDS IN FLIGHT AND CONTROL MEANSTHEREFOR Ronald Frederick Worlidge, Bognor Regis, England, assignor toFlight Refueling Limited, London, England, a British company ApplicationJanuary 17, 1950, Serial No. 138,954 In Great Britain January 18, 194918 Claims. 1

This invention relates to apparatus for transferring liquid in bulk fromone aircraft to another in flight, more especially for refuelling, andin which the part of the apparatus which is mounted in the receiver, 1.e. the aircraft to which liquid is to be transferred, comprises anexternally exposed coupling element referred to as a nozzlecoupling,having a liquid passage and stop-valve therein and provided withlatching means for engaging a necked nozzle element attached to the endof a hose trailed by the tanker, i. e. the aircraft from which liquid isto be transferred, and holding said nozzle element in liquid-tightengagement with the nozzle-coupling, the nozzle element beingpermanently mounted on the hau1 ing line and detachably connectible tothe hose.

An object of the invention is to render the operation of this apparatuslargely automatic, the intervention of the operatora member of thereceivers crewfor controlling the opera tions being reduced to the mereinitiation of required sequences of actions, which are then effectedautomatically.

A further object is to enable the necessary minimum of manual control tobe exercised remotely without actual handling of the mechanism; and atthe same time to provide the operator with appropriate visualindications of the state and operation of the apparatus.

Another object is the provision of automatic safeguards for protectingthe apparatus and reducing fire hazard in certain circumstances,especially in the event of an emergency breakaway, i. e. unintentionaldisconnection of the hose and nozzle element from the nozzle-couplingduring refuelling, owing e. g. to loss of formation between the tankerand receiver, the toggle means being constructed to release the nozzleelement on a critical load in the hose being exceeded.

How the foregoing objects and others as will hereinafter appear areaccomplished will be seen from the following description, havingreference to the accompanying drawings illustrating by way of example apreferred manner of "carrying out the invention, without limitation ofthe scope thereof, which is defined in the appended claims.

In the drawings,

Figures 1 and 1 which is a continuation of Figure 1, are a pictorialcircuit diagram of the installation in a receiver aircraft;

Figure 2 is a plan view, with the cover removed, of the power unit;

Figures 3 and 3 which is a continuation of Figure 3, are a stepped plansection of part of the power unit;

Figure 4 is an end elevation, partly in section, of the power unit, asseen from the left of Figure 2;

Figure 5 is a side elevation of the power unit with the cover removed toexpose the contents as seen from the right of Figure 4;

Figure 6 is a detail sectional view on the line 66 of Figure 3 Figure 7is a detail view showing the brush gear as seen in elevation from theleft of Figures 2 and 3;

Figure 8 is a rear view of the control panel;

Figure 9 is a plan view, partly in axial section, of the nozzle-couplingwith the nozzle in position for transferring fuel;

Figure 9 is a partial elevation viewed in the direction of arrow 9 ofFigure 9;

Figure 9 is a sectional view on the line 9 9 of Figure 9.

Figure 10 is an enlarged view, partly in axial section, of the nozzleand its attachment to the hauling line and to the refuelling hose;

Figures 11 to 17 illustrate diagrammatically successive stages in theflight refuelling operation using the apparatus illustrated in Figures 1to 10, and 18; and

Figure 18 is a perspective view of the hauling line and nozzle of thereceiver aircraft with the grapnel thereof engaged with the contact lineand projectile 0f the tanker aircraft.

The general arrangement of the system, as shown in Figures 1 and 1 willfirst be described. The system includes the following structural andmechanical components: a power unit l0 (see Figures 2 to 7) in which arehoused a Windlass II on which is reeled a hauling line l2, awindlass-driving electric motor l3, connected to the Windlass by a dogclutch I4, which is springloaded to disengage and is engageable by anelectro-magnet 15, a device 43 for locking the Windlass schematicallyrepresented in Figure 1 by a pin engageable by spring means (not shown)in an opening in the rim of the Windlass drum and disengageable by asolenoid 44 (see also Figure 2), a motor-pump unit It comprising anelectric motor l6 coupled to a hydraulic pump 16*, a hydraulic reservoirIT, a hydraulic pressure accumulator l8 comprising a cylinder I8, piston[6, piston rod 3 and spring I8 a solenoidvalve component [9, a governor20 driven by the Windlass through worm-gearing 2|, 22 and a shaft 23,which also drives the transmitter 24 of a distant-reading electricalcounter device for inpaid out, together with other items not shown 3 inFigures 1 and l a nozzle-coupling 25 (see also Figure 9), having a fuelpassage with two branches 26, 25 each provided with a stop-valve 21, 21a stop-valve-operating hydraulic jack 28 having a cylinder 28 piston 28*valve-closing spring 28, and piston rod 28 connected to the valves 21,2'! by links 29; and latch-engaging jacks 30 operative to engage latches(not shown in Figure 1*, but see Figure 9) with the neck of a nozzle 3|and secure it in the nozzle-coupling, the nozzle being permanentlymounted on the end of the hauling line I2 and being provided with meanshereafter referred to for attaching it to a hose paid out from thetanker aircraft. The nozzle can be hauled into the nozzle-coupling bymeans of the hauling line, which passes through a fairlead in the centreof the nozzlecoupling; and the latches are disengageable by spring meansas shown in Figure 9.

The hydraulic circuit comprises a pressure main 32 connected to thedelivery side of the pump IG a suction main 33 connected to the suctionside of pump IG and to the reservoir ll, a branch 34 connecting thepressure main to the accumulator |8, non-return valves 35, 36 in thepressure main on either side of the connection to the accumulator branch34, and by-passes 37, 38 connecting the pressure and suction mains, theformer containing'a relief-valve 39 normally closed by a spring 39 andthe latter a control valve l9 loaded to open by a spring I9 and closableby a solenoid |9, the'valve and the solenoid together constituting thesolenoid-valve component IS. The pressure main 32 is connected by abranch 4|) with the valve-operating jack 28 and by a continuation pipe4| having branches 42 with the latch engaging jacks 3D. The arrows inFigure l indicate the direction of flow when the pump |6 is working withthe control valve l9 closed. The pipes 40, 4| are provided withrestrictors (not illustrated) which ensure that the stop-valves 21, 2%open more slowly than the latches engage.

The system is remotely controlled and its operation monitored by switchand indicator means mounted on a control panel 45 (see also Figure 8)and comprising a ganged three-position'master switch 46, a mainindicator lamp 4?, a hydraulic indicator lamp 48, an emergencybreak-away indicator lamp 49 and a hauling line indicator 50 having ascale 50 and pointer 50* indicating the length of hauling line paid outand constituting the receiver which is electrically connected to thetransmitter 24 by conductors The electrical circuits (see also Figures 5and 8) are shown as wired on the single pole system with ground returnas indicated at G. The positive feed, indicated at is connected to apositive main 55 having a parallel branch 52. Branch 52 is connected byconductors 52*, 52 to the two ganged moving contacts 53, 54 of themaster switch 46, and the main 55 is connected through a switch 56 withparallel conductors 51, 53, conductors 51 being connected to the inputterminal 58 of the Windlass motor l3 and conductor 59 to the inputterminal 60 of the clutch magnet I5 to which the current is passed bymeans of a brush 6| and a slip ring 62. The main 55 is further connectedthrough a switch 63 with the input terminal 65 of the pump motor Ili Themaster switch 46 has three fixed contacts 66, 61, 68. In one position,called 01f both arms '53, 54 are clear of all fixed'contacts and allcircuits are open; in a second position, called trail arm 53 is clear offixed. contacts and arm 54 1s closed on contact 65, and in the thirdposition, called wind arm 53 is closed on contact 68 and arm 54 oncontact 6'1. Contacts 66, 57 are both connected to a conductor 69 andcontact 58 to conductors 1 I, l2; Therefore in the wind positionconductors 69, H, 12 are all alive and in the trail position onlyconductor 59 is alive.

Conductor 69 has two parallel branches 69, 65 of which branch 53 isconnected to the solenoid 44 which when energised withdraws the pin 43from the Windlass drum to release the Windlass; and branch 39 isconnected to the transmitter 24 to energise the latter and cause it totransmit impulses by means of the conductors 5| to the receiver in theindicator 55 to move the pointer 55 so as to indicate the length ofhauling line paid out. The circuit through branch 59* and thetransmitter 24 is completed by a ground connection H3. The constructionof the transmitting and receiving elements of this device is notillustrated or described as many successful systems are well known andthe details of this distant-reading indicator are not per se part of theinvention. Furthermore, conductor 69; is connected to the main indicatorlamp 4?. Therefore, when the switch 46 is in the trail or wind positionthe lamp 4'! is illuminated, the Windlass is free and the hauling lineindicator is operating.

To conductor 12 the indicator lamps 48, connected in parallel.

Conductor H is connected to three solenoids, viz. solenoid |9 whichcloses valve I5 solenoid i3 which closes switch 55 and solenoid '64which closes switch 63.

The return path from solenoid i9 is by way of a conductor 90 which isgrounded through a switch 9|. The return path from solenoid i3 is by wayof a conductor 15, a switch H3 and a conductor Tl connected to one fixedcontact 15 of a two-way switch 78, of which the moving contact isgrounded. The return path of solenoid 14 is by way of a conductor 19connected to one fixed contact 8% of a two-way switch 80, the movingcontact of switch being connected to the conductor 99 by means of aconductor 95 The second contact 80 of the switch is connected by aconductor 92 to the hydraulic indicator lamp 48, the circuit throughwhich is completed to ground through conductors 92 and and switch 9|when the moving contact of switch 85 is closed on the fixed contact 55Thus, completion of the circuit through solenoid l9 requires only thatthe switch 9| be closed, whereas completion of the circuit throughsolenoid 53 requires closure of the switch l5 and closure of the switch18 on the fixed contact 18 and completion of the circuit throughsolenoid M requires closure of the switch 80 on contact 80 as well asclosure of the switch 9|. Switch Si is mounted on the nozzle-coupling 25and is closable by the nozzle 3| on entering the coupling (see alsoFigure 9). Switch 76 is arranged to be normally closed but to be openedwhen the stop-valves 21, 2'1 of the nozzle-coupling 25 are fully opened,the actuating means being diagrammatically represented in Figure l by aramp 94 on the piston rod 28 of the jack Z8 and so disposed as to openthe switch IE5 when the piston 28 of the jack reaches the position inwhich the valves 21, 2'1 are fully open. Switch 78 is operated by thegovernor 23; it is normally closed on the contact 13 but when the speedof the Windlass exceeds a critical value the governor shifts the movingcontact 18 from the fixed con-tact 18 to the other fixed contact 49 areswitch 9 I 18 of the switch to close the circuit through the emergencybreak-away indicator lamp 49 through a conductor 93 and conductor 72.

The two-way switch 80 is operated by the hydraulic accumulator I8through a lost motion connection diagrammatically represented in Fi ure1 by a longitudinally slidable bar 95 having a cam-slot 96 engaging apin 80 on a link 80 connected to the moving contact of switch 80 and anelongated recess 91 engageable with a pro ection 98 on the end of thepiston rod I8 of the accumulator I8. When the accumulator is fullydischarged and the spring I8 is fully extended, projection 98 engagesthe right hand end of the recess 91 and causes the cam-slot 96 and link80 to throw the moving contact of switch 80 onto the fixed contact 80completing the circuit of the solenoid I4 through conductors I9 and 90and When the accumulator I8 is filled with hydraulic fluid by the pumpI6 the piston I8 moves to the left, as seen in Figure 1, compressing thespring I8 but the bar 95 is not moved from the position in which themoving contact of switch 80 is closed on contact 80 until the pressurein the accumulator I8 has reached an upper predetermined limit,compressing the spring I8 and causing the projection 98 to meet the lefthand end of the recess 9'! and move the bar 95 to the left, as seen inFigure 1, thereby causing the cam-slot 96 and link 80 to return themoving contact of switch 80 to the fixed contact 80 Similarly, when theaccumulator I8 discharges, the moving contact of switch 80 remainsclosed on the fixed contact 80 until the pressure in the accumulatorreaches a predetermined lower limit. Thus, when the accumulator becomescharged, the circuit through solenoid 34 is broken and the switch 63 isopened to deenergise the motor pump unit I6 and the hydraulic indicatorlamp 48 is illuminated; and the motor pump remains inoperative and thehydraulic indicator lamp illuminated until the accumulator becomesdischarged. It will be noted that the accumulator-operated switch 00does not affect the action of the solenoid I9 which remains energised toclose the valve I9 and retain pressure in the hydraulic connection 32,34, 40, 4| as long as the input conductor II is energised and the switch9| in the ground return circuit through conductor 90 is closed.

The construction of the power-unit I0 is illustrated in Figures 2 to '7.It comprises a casing assembly including a casting 99, end plates I00,WI and sheet metal cover plates I02, I02. The casting 99 has webs 99 99*forming internal partitions. The end plate IOI is dished inwards (seeFigure 3) and is formed with a hollow central boss I0I to the outer faceof which the motor I3 is secured by studs I04. Boss IIII'= carries abearing I05 on which the windlass drum II is supported coaxially withthe motor, and a second bearing I06 (see Figure 3 carried in a boss I00of the end plate I00 supports a hollow shaft I I having a dished flangeII bolted to the drum I I. v

The motor is connectible to the windlass by means of a dog-clutch (seeFigure 3) of which one dog I0! is fast on the motor shaft and the otherI08 has a short shaft slidable on splines in a boss I09 bolted to thedrum II, and is urged to disengaged position by a compression spring II0 trapped between the boss I09 and an abutment plate III secured to theshaft of the dog I08 by a stud H2. The dogs I01, I08 have but- -tressteeth whose driving faces d are slightly laidback to facilitatedisengagement, the rear faces 1' being inclined at a small angle to theradial plane to facilitate engagement. The dog I08 is engageable withdog I0'I by means of an electromagnet comprising an iron-circuit memberII3 having integral lugs II3 by which it is bolted to the drum II andenclosing an annular winding H4, the armature of the ma netbeingconstituted by a control plug I I5 secured by an adjusting screw II6 toa thimble II'I axially slidable in the member II3 to bear on the head ofstud H2. The movement of the armature is limited in the disengagingdirection by the end face of shaft I I and in the engaging direction bythe member H3, and the screw II6 enables the relative positions of thearmature H5 and dog I08 to be correctly adjusted to ensure that the dogsI01, I08 are fully engaged when the armature meets the member II3 toclose the magnetic circuit. The ends of the winding II4 are respectivelyconnected to a conductor II 8 grounded to the drum shaft flange II andto an input conductor II9 connected by a stud I and washer I2I to aslip-ring I22 secured to the flange I I by studs I23 carrying insulatingbushings I24. Brushes I25 (see Figure 7) carried in insulating holdersI25 mounted on a bracket I26, which is bolted to the box I66 hereinaftermentioned (see Figure 3 convey the input current to the slip-ring I22.

In Figure l the windlass-locking device is schematically represented bya pin 43 entering an opening in the rim of the windlass drum. Thisarrangement would be harsh in operation and would cause damage if themaster switch were inadverently thrown into the off position while thewindlass was turning. In the actual construction (see Figure 2) thelocking device is constituted by a friction pad 43 pressed against therim of the windlass drum II by a spring 44 abutting on a housing 44secured to the casing end plate I00 and enclosing the solenoid 44 (seeFigure 1) which withdraws the pad 43* when energised. 1

Shaft II is provided with a worm I21 meshing with a worm wheel I28 on ashaft I29 supported in bearings I30 carried in brackets formedintegrally on the casing end plate I00 (see Figure 3*). Shaft I29 drivesa serving gear for laying the hauling line I2 onto the windlass drumevenly. A bevel pinion I3I on the end of shaft I29 drives a bevel pinionI32 on a shaft I33, parallel to the windlass drum axis and supported inbearings in the casing end plates I00, IOI, the shaft I33 having rightand left hand Archimedean screw threads I34 engaged by a slipper (notshown) carried in an extension I35 of a housing I36, which is slidablysupported on a guide I31 secured at each end to the casing end platesI00, IOI. Housing I36 supports freely rotatable grooved rollers I38 andguide pins I39 between which the hauling line passes. When the windlassrotates the Archimedean screw I34 causes the above-mentioned slipper andthe housing I36 to travel back and forth along the guide I31 to lay thehauling line evenly on the drum I I.

The reservoir I1 is mounted above the windlass with the motor-pump unitI6 alongside it. A double banjo I40 connects the suction inlet of thepump I6 to a suction stand-pipe 33 in a reservoir and to the return line33 of the hydraulic system while the delivery outlet of the pump isconnected by a banjo I 4| to the pressure main 32 The pressure andsuction lines 32%, 33 are connected to a junction box I42 containing thenon-return valves 35 and 36 and relief valve 39 of Figure 1 (not shownin Figures 2, 4 and 5), and having connections to the hydraulicaccumulator I8 by means of a pipe 34 and to the solenoid valve componentI9 (see Figure 5) by pipes 38 538 the latter being also connected to apipe 32 terminating in a union I43 for connection to a hydraulic serviceline (not illustrated), which feeds the toggle-engaging jacks 30 andstop-'valve-ope'ning jack 28 (Figures 1 and 9). The junction box I42,pipes 38*, 38 and 32 and the solenoid valve unit I9, the casing of whichencloses the control valve I9 spring I9 and solenoid I9 of Figure 1 (notshown in Figure 5), are housed in a compartment I44 of the main casingshown at the bottom right hand corner of Figure 4 and in Figure 5, theaccumulator I8 (see Figure 4) being in the main compartment next tocompartment I44, and the accumulator operated switch 80 and operatingmechanism 95-98 of Figure l (not shown in Figure 4) being enclosed inthe casing of the accumulator.

Since the actual hydraulic circuit illustrated in Figures 2, 4 and 5differs in detail from that diagramatically illustrated in Figure 1though functionally equivalent, distinguishing affixes a and b areapplied to corresponding reference numerals in Figures 2, 4 and 5. Thusparts 32 and 32 (Figures 2, 4 and 5) correspond to part 32 of Figure 1and so forth.

The Windlass is provided with a brake in the form of a displacementair-compressor of the vane pump type (see Figures 3 and 4) of which therotor is constituted by a hub I46 carrying radially slidable vanes I41,and the stator by a housing I48 secured to the outside of the casing endplate I and enclosing a chamber I49 in which the rotor rotateseccentrically with the vanes sweeping the internal peripheral wall ofthe chamber, the clearance between each vane and the chamber-wall beingsealed by strips I50 radially slidable in the vane and pressed outwardsby springs II. The hub I 46 has integral stub shafts I52, I53, the outerstub shaft I52 being supported by the housing I48 in a bearing I54 andthe inner stub shaft I53 being connected by a splined joint with theWindlass extension shaft H The housing I48 is peripherally groovedinternally to form inlet and outlet manifolds I55, I56, the formerconnected with an atmospheric opening I51, and the latter with a reliefvalve comprising a seating 2I2, a valve-needle 2I3, apertured cover 2I4,spring 2I5, spring abutment 2I6, and abutmentadjusting screw2I1. Apocket I 59 communicating with the outlet manifold contains a variablythrottling outlet valve (see Figure 3 comprising a hollow, open-endedpiston I59 having ports I60, and a thimble I6I having atmospheric ventsI62, in which thimble the piston slides. The piston I59 is biased to aposition, in which the ports I60 are uncovered thus venting the chamberI49 freely to atmosphere, by a compression spring I63 trapped betweenthe thimble I6I and a flange on the piston I59. The piston I59 also hasan integral stem I 59 slidably supported in the casing end plate I00 andengageable by the end of a lever I65 pivotally mounted in a box I66secured to the inner face of the plate I00 by studs I61; and when thepiston is moved by the lever I65 against the effort of spring I63, theports 60 are progressively closed, thus progressively throttling theoutlet of the vanepump I46'I5I and thereby increasing the re- 8 sistingtorque on the Windlass at any given speed of the latter. A tubulardistance piece I64 mounted on stem I59 limits the displacement of thepiston I59 under the effort of spring I63.

A shaft I68, supported in the box I66 in bearings I69 coaxially withshaft I29 and driven thereby through dogs I10, has formed thereon alead-screw I1I, with which a nut H2 is in threaded engagement. A guiderib I13 prevents the nut from rotating. When the hauling line I2 isfully wound in, the nut I1I is in the position shown in dotted lines inFigure 3 As the hauling line is paid out the rotation of shaft I29, I68causes the nut to travel down the lead-screw "I, the displacement of thenut being proportional to the length of hauling line paid out. When apredetermined length of line has been paid out the nut reaches aposition in which it meets the lever I65 and further advance of the nutas the hauling line continues to pay out causes the lever I65 to berocked counterclockwise to close the ports I of the outlet valve I59-I62progressively. Since the lever' I is disposed at an acute angle to theaxis of the lead-screw HI and so orientated that as the nut I12 advancesin contact with it this angle increases, the rate at which the valveports I60 close relatively to the rate of advance of the nut increasesprogressively. The resisting torque imposed by the vane' pump on theWindlass is therefore negligible until the nut I12 reaches the lever I65and thereafter increases progressively at an increasing rate as the nutadvances. For an given position of the valve piston I59, this resistingtorque is approximately proportional to the square of the paying outspeed of the Windlass, so that the latter experiences no substantialresistance when turning slowly.

Owing to the positions of the outlet and relief valves and the inletopening the vane-pump is only operative when the rotor I46 rotatescounterclockwise as seen in Figure 4 corresponding to rotation of theWindlass in the direction for paying out the hauling line. When thelatter is being wound in the rotor I46 rotates anticlockwise and theinlet I51 becomes an unobstructed outlet, so that no appreciableresistance is imposed on the Windlass irrespective of Whether the portsI60 are open or closed.

The nut I12 also serves as a counter for the length of hauling line paidout and is connected by a link I14 (see also Figure 5) with thetransmitter 24 of the distant reading hauling line indicator (see Figure1), the transmitter 24 bein g gnuseg in a compartment I15 of the casingCompartment I15 also houses the governor 20 which comprises a housingI16 secured to the box I66 and enclosing a rotary carrier I11 driventhrough speed multiplying gearing by shaft I68 and having pivotedthereon flyweights I80, the toes of which engage the outer race of abearing I8I, whose inner race is fast on a shaft I82 slidable in athimble I83 screwed into a housing I16 and having a spring abutmentcollar I94 between which and anabutment plate I85 fast ora sthe shaftI82 is trapped a compression sprin The gearing by which the carrier I11is driven comprises a pinion I19 fast on the end of shaft I68 a pinionI11 integral with the carrier I11, and an idler gear I18 having a largediameter gear element In -meshing with pinion I11 and a small diametergear element I18 meshing with pinion I19 (see Figure 6).

On the end of the housing I18 is attached a switch box I81 enclosing aswitch comprising the moving contact 18 which is secured to the end ofshaft I82 and grounded therethrough, and the two fixed contacts 18" and18 (see Figure 1) the contact I8 being normally closed on contact 18 butdisplaced by the flyweights I39 against the effort of spring I89 toleave contact 18 and close on contact 18 when the Windlass exceeds acritical speed.

A detachable handle 2| I (see Figure 3 is provided, which can be fittedto the end of shaft I52 for the purpose of operating the Windlass I I byhand when power is not available, e. g. for unwinding and re-winding thehauling line I2 for inspection purposes.

Figures 9, 9 and 9 illustrate the nozzle-coupling and nozzle andassociated details. lhe coupling 25 comprises a nozzle-receiving bellI88 to which is connected a fuel conduit having two branches 26, 29 inwhich are arranged stopvalves constituted by flaps 21, 21 Secured toeach branch of the fuel conduit by means of a I bracket 292 is ahydraulic jack 28, of which the piston 28 is loaded by a compressionspring 28. A union 49 on the head of each jack 28 connects the latter toa branch, corresponding to branch 49 of Figure l of the hydraulicservice line (not shown) connected to union I43 of Figure 5. Admissionof hydraulic pressure to the jack extends it against the effort ofspring 28. The piston rod 28 of each jack terminates in a fitting 28which is slotted at 28 to receive a bolt 293 which connects a yoke 294to a lever 295. Yoke 294 is connected to an anchorage plate 298 securedto the head of the jack by tension springs 189 which assist the effortof spring 28 in shortening the jack. Lever 295 is mounted on a shaft 298supported in bearings in the conduit-branch 29 or 28 and carrying aninternal lever 291 on which the fiap 21 or 21 is mounted. The flapvalves 21, 21 are normally kept closed by the springs 28, I89 but areopened by the jacks 28 when the latter extend on admission of hydraulicpressure.

In this constructional embodiment the switch 16 of Figure l isduplicated, a switch 16 being associated with valve 21 and a similarswitch 19 with valve 21*. These switches are mounted on brackets 299secured to the conduit-branches 28, 28 respectively and are engageableto cause them to open by integral projections 2I9 of the yokes 294 whenthe jacks 28 are fully extended and the valves 21, 21 fully opened. Toensure that the circuit 15, 11 (see Figure 1 will remain closed untilboth valves 21, 21 are open, the switches 15, 19 are connected inparallel in the circuit 15, 11.

On the outside of the bell I88 are mounted brackets I99 on which arepivoted latch-levers I9I. The ends of these levers can pass throughslots in the bell to engage the neck of the nozzle 8| and draw thelatter into and secure it in the nozzle-coupling 25. Tension springs I92and coil springs I93 rock the latch-levers outwards to clear the nozzle3| as it enters the coupling 25 and to allow it to leave the coupling,and hydraulic jacks 39 pivotally anchored on the coupling structure areconnected to the latch-levers to rock them inwards to engage the nozzle,the jacks being arranged to shorten under application of fluid pressureto their working chambers.

The jacks 39 are connected by pipes 42 with the hydraulic service line(not shown) which is connected to union I43 as mentioned above.

The nozzle-coupling 25 is provided with a central fairlead I94 throughwhich the hauling line I2 is rove, and the end of the hauling line I2 isattached to the base of a tubular plug 2 I8 formed integrally with thenozzle 3| to the body of which it is connected by radial webs 2|9 (seeFigure 10). Plug 2|8 fits into a socket 229 formed integrally by meansof radial webs 22I with a hollow nozzle-connector member 222 which ismounted on the end of the hose I91 and on the outside of which thenozzle 3| fits in a fluidtight manner. The plug and socket coupling 2I8, 229 is provided with a ball-catch constituted by balls 223 lodged inradial openings of the plug 2 I8 and engageable in an annular grooveformed in the inner wall of the socket 229, and a tubular plunger I95provided with a ball-receiving annular groove 224 mounted to slide inthe plug 2|8 between limit stops. The plunger is loaded by a lightspring 225 the effort of which must be overcome to slide the plungerinto the ball-releasing position. The nozzle-connector member has aclosure valve 226 normally held on its seating by springs 221 (seeFigure 19), but which can be unseated by plungers 228 slidably mountedin the radial webs 2 I9 of the nozzle and carrying a nozzle tip ring229, which is pressed inwards against the effort of springs 239, tounseat the valve 228, when the nozzle 3| is drawn fully home into thenozzle-coupling 25 by the latch-levers I9I, as shown in Figure 9. Theexposed end of the plunger |95 is enlarged and carries hinged,spring-loaded grapnel arms I99.

The switch 9| (see Figure 1 is mounted on the fairlead I94 behind thenozzle-coupling, and its external operating member I98 is connected to a"Bowden cable I99, whose other end is connected to a trigger 299 pivotedon a bracket fixed to the outside of the bell I88 to project through aslot into the interior of the bell. A tension spring 29| acts on theexternal switch member I98 to move it to the position shown in dottedlines in which the switch 9| is open and to cause the trigger 299 toroject into the bell I88 as shown in dotted lines. When the nozzle 3| isfully home in the bell I88, the trigger 299 is rocked into the positionshown in full lines to close the switch 9|, which is returned to theopen position by spring 29I when the nozzle 3| leaves thenozzle-coupling 25.

The neck of the nozzle 3| is so shaped that the tension in the hose I91continuously exerts a force on the latch levers opposed to the engagingforce exerted by the jacks 39, and if the tension in the hose reaches avalue at which the backpressure exerted on the hydraulic system by thejacks 39 is sufficient to lift the relief valve 39 (see Figure 1 andenable the jacks 39 to empty, the latch levers will rock outwards andrelease the nozzle.

The operation of the system will now be described. Initially the masterswitch 48 is in the off position, rendering all the electrical circuitsdead; all three indicator lamps 41, 48, 49 are extinguished, the haulingline indicator 59 is not functioning and the Windlass H is locked bymeans of the device 43. On receipt of a signal from the tanker aircraft13 (Figure 11) that it has taken up station and is ready to commencerefuelling, the receivers operator in the receiver aircraft A (Figure11) places the master switch in the trail position, thus energisingsolenoid 49 to withdraw the device 43 and release the

